Attic ventilation



Feb. 27, 1940. L EED 2,191,774

ATTIC VENTILATION Filed March 20, 1959 k 2 Sheets-Sheet 1 M 3 Arr/c SPACE /6 5 sucr/o/v awn/v55? 5 FAN 1 CHAMBER C ILI YG Ll/VE an 6'. fleecl L. c. REED 2,191,774

ATTIC VENTILATION Feb. 27, 1940.

Fi l ed March 20. 1939 2 Shets-Sheet 2 l3 35 M Ca /Z Patented Feb. 27, 1940 PATENT OFFICE ATTIC VENTILATION Lyman C. Reed,

New Orleans, La.

Application March 20, 1939, Serial No. 262,943

9 Claims.

This invention relates to ventilation and more particularly to means for controlling ventilation, having for its object to provide a construction simple in parts and more eflicient in use than those heretofore proposed.

With these and other objects in view the'in-' vention resides in the novel details of construction and combinations of parts as will be dispointed out in the claims.

Referring to the accompanying drawings forming a part of this specification and in which like numerals designate like parts in all the views Fig. 1 is a somewhat diagrammatic view in substantial vertical section of an installation of one form of this invention;

Fig. 2 isv a diagrammatic illustraticn on an enlarged scale of the operation of one of the louvre vanes shown in Fig. 1;

Fig. 3 is a diagram of values incident to a louvre vane in various of its positions including the closed position;

Figs. 4 to 9 inclusive are diagrams illustrating modifications of the application of coil spring pressures to a louvre vane;

Fig. 10- is a diagram illustrating a modification of the construction shown in Fig. 2 and wherein the pressure of a leaf spring is employed;

Fig. 11 is a fragmentary end elevational view of a plurality of louvre vanes interconnected and controlled in a manner different from that shown in Fig. 1 but involving the same principle of this inventiomand Fig. 12 is a fragmentary perspective view illustrating a modified form of vane mounting.

This application constitutes a continuationin-part of my application filed January 6, 1988, under the Serial No. 183,699 and entitled Attic ventilation.

40 Prior constructions of similar type provide means for opening and closing an air vent in accordance with the desired flow of air, which means generally comprises a plurality of hinged louvre vanes or air valves so arranged as to be closed when no air is flowing, and to be open when air is flowing through said vent. Such louvres have most commonly been incorporated in windows but in the following disclosure an application of such louvres is shownas embodied for example in a ceiling for controlling the air drawnlfrom the house proper into the attic space from which it can escape to the atmosphere outside of the house due to the fact that the attic space is in most instances not sealed with respect to said outside atmosphere. Louvres closed more fully hereinafter and particularly should be maintained closed when no air is in- I tended to flow therethrough, for otherwise insects can enter the house. The heretofore known structures, however, have generally provided louvre vanes mounted upon a vertical axis, or 5 vanes freely hanging from a horizontal axis, with no positive means for holding the louvres shut,

as a result of which the vanes have been noisy when closing and are subject to flap open, due

to vacuum suction when winds are blowing and 10 the fan is not in operation, producinga clattering noise which is objectionable. If manual means were provided for locking or holding the vanes in closed position, in many instances such means are forgotten, with the same objection- 15 able results. Whenever any means was provided for preventing this clatter, it has been in the nature of a mechanism for holding the louvre vanes in closed position.

The present invention is directed to a construction which will overcome the heretofore known disadvantages, and broadly is directed to a louvre vane so constructed that it will be heavy enough normally to remain closed under conditions of actual draft normally experienced, butv which will have operatively associated therewith means tending to open the louvre, the forceexerted by said means however being less than the weight of the louvre vane. Thus it will be understood that' vanes of considerable weight, relatively speaking, can be employed according to this invention, and/or vanes of considerable size will be found practical, though no limitation of size and/or weight, and therefore no limitation as to the nature of the material of the vane, is contemplated.

As will be seen from Fig. 1 an embodiment of the invention is shown mounted in the attic space of a house, above the vent I provided in the attic floor, and through which vent air may pass as indicated by the arrows. If desired an ornamental grille 2 may be placed over this vent on the ceiling line. In the attic space there is provided a casing, generally identified by the numeral 3, which is divided by a partition 4 into a suction chamber (communicating with said vent) and a fan chamber, said partition having the aperture 5 therein, the opposite wall of the fan chamber having the aperture 1 therein, so that, the air from the house may be drawn through the vent l into and through the suction and fan chambers, and in the direction of the arrows 8 into the attic space when the fan (not shown for clearness) in the fan chamber is operating.

rectly over the vent l is any suitable framework indicated at Ill in which is mounted a plurality of louvre vanes such as H, arranged parallel to each other as usual and of substantially equal dimensions, each vane pivotally supported upon a horizontal shaft or axis l2 and having an operating lever l3 on the opposite side of said shaft, which lever is disposed obliquely to the main body portion of the vane. In other words each vane may be formed rectangularly of sheet metal and may have the operating lever attached thereto at substantially the pivot point, or the shaft may be angularly bent in the form of a crank set at the proper angle from the plane of the vane, in Figs. 1 and 2 the angle of inclination of the lever l3 to the vane proper being of the order of 135. All of the levers are of substantially equal dimensions and similarly inclined to their vanes.

A tie rod i4 is provided below the horizontal plane of all the axes of the vanes, and disposed substantially at right angles thereto, and to said, tie rod is linked the free end of each vane lever l3 thus providing interconnection of all of the as the louvre frame Ill. The members l4, l6

and I1 preferably should be in a substantially common line of movement, though in Fig. l for clearness the members l6 and I! are shown out of line with the tie rod M. It will be understood that one or more tie rods may be provided, each tie rod interconnecting the free ends of the levers l3 of all of the vanes, and that itwill be further understood that one or more springs such as I! can be provided according to the size and weight 'of the vanes and levers.' In other words there can be a tie rod'disposed at one end only of the series of vanes or there can be a tie rod at each end thereof, or a tie rod may be provided intermediate said ends, with either a single spring association with one of the tie rods or a spring for each tie rod. In Fig. 1 all of the vanes are shown in open position by the full line representation, and are indicated in closed position by the dotted line representation.

In Fig. 2 there is-illustrated (on an enlarged scale) a singlevane H with its lever l3, and for the sake of clearness the tie rod II has been omitted, the end of the lever I3 being shown connected to a link such as l6 to which the spring I! is fastened, with the free end of the spring anchored to any suitable fixed support such as the frame l above described, I8 representing a stop member against which the vane abuts when in closed position, such stop member being an independent structure and/or a portion of the next adjacent vane.v The dotted line representation in this figure of the drawings indicates the vane in open position at H and the lever moved to a corresponding position at l3. Thereforeit will be understood that the end of the link IE to which said lever is secured will have moved to the position shownfin dotted lines at I6 thereby shortening the elongation of the spring I! and reducing the tension thereof.

The weight of the vane must be such that the gravitational pull indicated by the arrow 19 will be greater than any tension of the spring in order to maintain said V cm its closed position,

but the differential between this gravitational Within the suction chamber and mounted dipull and said spring tension, must be less than the suction force of the fan (when operating to the vanes closed, and that this force of the spring makes possible a reduction in the amount of the fan suction necessary to hold the vanes open. Hence, advantages are attained in a reduction of revolutions per minute of the fan with corresponding reduction in noise, and/or a saving in current consumption by use of less powerful fans. In addition, it is a well known fact, that appreciable air restriction, and hence loss of efliciency, results when louvre vanes are opened only to small angles andtherefore, by this invention, a higher degree of efficiency is obtained because the assisting spring I! enables the vanes to be opened to much greater angles than is now the case.

In order for the heretofore known or conventional louvre vane to operate without excessive air restriction, it is constructed of very light gauge metal and generally of such metal as aluminum. When the vane is mounted so as to be in a horizontal plane when closed, the greatest gravity force is operative when the vane is in closed position, and said force becomes less as the angle of opening increases, following the cosine law as regards gravity pull at various angles. It would seem to follow, therefore, that any air current of constant value with sufficient force to start the opening of the vane would carry the vane to a vertical or full open position. However, in actual practice, this result is not obtained when a fan is mounted so as to establish air flow in a direction which is at right angles to the plane of the vertically open valve.

Referring again to Fig. 2 the vane l I is shown in full lines in its closed position and is shown in dotted lines at H in open position, and to make more clear what has been described above certain values will now be assigned to the various forces acting upon said vane. Assuming, therefore, that the gravitational pull on the closed vane at 19 is 7 lbs., and that the spring pull on lever I3 is lbs., and that the force of the air current established by a fan is 3 lbs., it is evident that when no air current force is exerted the vane will remain closed due to the differential of 2 lbs. between the 'gravitational pull and the spring tension. However, when the air current force of 3 lbs. is exerted upwardly on the closed vane, the vane will move upwardly to open position because said 3 lbs. force is greater than the 2 lbs. differential. When the vane reaches the dotted line open position at II the angle of opening is (assumedly) 45 but lever l3 will have.

been moved to dotted position l3 causing a shortening of the elongated spring with coincident reduction of its tension; at these positions the gravitational pull on the vane is 4.9 lbs. (instead of 7 lbs.) the air force is 3 lbs., and the spring tension is 4 lbs. wherefore the vane will easily remain open because the sum of the air force and the spring tension is greater than the grayitational pull. When the air force is removed, the'van'e will return to closed position because the gravitational pull is greater than the spring tension. With the values .pust given it is evident that the vane could not be advanced much beyond a 45 opening to make it self -closing when the air current force was removed but, by varying the relative values of gravitational pull and spring tension, various angles of opening may be obtained up to the point where a balance is reached between the gravitational'pull and the 5 sum of the opposing forces exerted by the upward air pressure and the ,spring tension.

The development of this spring-assisted louvre vane is a distinct adv nce in the art, as materials of any required we ig'ht (includingsteel of substan- 10 tial weight) can be used. The opening and closing of theya'n'e under various air pressures is a functiomfdf the relative values of spring tension, gravitational pull, and air pressure, and hence notof gravity and air pressure alone as in here- 5 t6fore known constructions. Various angles of opening may be designed into any given louvre vane by varying the relation of spring tension to gravitational pull. It is also obvious that the anglebetween the'vane and its lever can be so 20 changed as to give different results with the values of air pressure, gravitational pull and spring tension remaining the same as above recited. Vanes disposed, in their open positions, at an angle to the direction of airflow keep 25 down or reduce vibrational noises and increase the efiiciency of the air movement through the casing 3 by reducing the .air turbulence caused by change of direction of the air flow from a vertical path to a horizontal path. One of the 30 essentials of a louvre vane is quietness in operation, especially when installed in a house and subject to night operation when any rattle, clatter, or undue noise may disturb the occupants. In the louvre vane construction he'rein disclosed 35 there has been provided a spring power which, applied to the operating lever l3, keeps the vane under tension, resulting in'no rattles nor flapping. This is a marked improvement since heretofore known vanes are built loosely so as to offer little friction and in consequence have been noisy.

, With reference to Fig. 3 there are shown, diagrammatically, values applied to a louvre vane in various of its operating positions from closed 5 to 60 open, in this figure of drawings it being assumed that the single vane illustrated represents a series or multiple set of vanes such as shown in Fig. 1 and having a downward gravity pressure (or gravitational pull) of '7 lbs. Also, 50 in this Fig. 3 the vane and its lever are shown in full lines at closed position, in long dashes at 15 open position, in dash and single dot lines at 30 open position, in dash and two-dot lines at 45 open position, andin dotted lines'at 60 55 open position, in order to clearly differentiate said positions the vane and its lever is 150 (or 60 for the purpose of calculations). Therefore, with the vane in closed position, a spring of 6 lbs. normal tension, attached atone end to the lever and anchored at itsother end to an immobile structure, will have an efiective. pull of 3 lbs. since it operates under the law of cosines and the cosine .of angle 60 is 0.5 (i. e. the efiective pull 5 equals the product. of the spring tension and the cosine of angle 60). Hence, it is evident that. there is a differential of 4 lbs. between the gravitational pull of 7 lbs. and the effective pull of 3 lbs. of the spring, and this differential is sufii- 70 cient to maintain the vane closed when no air flow is induced by the'fan.

' However, when the air flow is induced in an amount sufiicient to exceed this differential, the vane starts to open. As the vane opens, its 75 gravity pressure decreases in ratio-to the cosine Further, the fixed angle between of the angle ofopening. Likewise, the spring pressure increases in ratio to the same cosine law, but another factor now enters the situation, in that thespring exerts a smaller inherent pullon the lever at say a position of 45 in direct ratio 5 to its elongation at the start (closed vane position) and its present shortened position. Therefore, the spring pull at the 45 position of the lever (15 vane opening) is the product of the new spring pull'(shortened spring) at that point 10 and the cosine of 45 (0.7) resulting in the effecitve spring pull of 371 lbs.

In similar manner, Fig. 3 shows the various values of the gravitational pulls and spring tensions (actual and efiective) of the vane at the opening angles indicated. From these values it will be noted that the ratio of gravity pressure to spring pull increases in favor of the spring as the vane opens, which is a very vital factor in its operation as the air pressure on the opening vane is constantly decreasing until at maximum opening, when the air pressure drops to a small percentage of its original effective value. In this illustration, the air pressure would have to be 'less than 1 lb. to balance the spring and gravity pulls, whereas at the closed position of the vane it must exceed 4 lbs., to start the opening movement of said vane. In addition to the previously mentioned variations permissible in the spring tensions and angles of inclination of lever to so vane, it is evident that for any given flow pressure, vanes of any desired weight can be used if the corresponding spring pull is used. In other words, the air pressure has only to take care of the differential between gravity and spring pulls, wherefore vanes of any desired material can be used, and maximum vane opening angles of the order of 60 can be obtained from air pressures that could not be handled by louvre constructions now known. A louvre designed for a 60 40 vane opening has been perfected in accordance with this invention and its operation is successful in every way; this same louvre without the proper spring pull applied thereto will open to only 20 under the same air pressure, and'if the vanes were constructed of still heavier metal than they are, no opening movement would occur.

In Figs. 4, 5 and 6 are indicated modifications of the construction illustrated in Fig. 2 and according to which it will be seen that the operating lever l3 may form an acute or an obtuse angle with the vane H, and may be disposed above or below the horizontal plane of the vane axis or pivot l2. Such differences of lever location call for various dispositions of the spring H as shown, wherefore said spring may be horizontally disposed above or below the pivot, or it may be vertically disposed to either side thereof, but always the force of said spring tends to produce opening movement of the vane H.

. In Fig. 7 the leverage on the vane is not applied at the pivot I2 but at a point spaced therefrom through the provision of the lever arm 25 rigidly secured to the vane and extending substantially at right angles therefrom at a point between the pivot 12 and the free opening edge of the vane. The spring I! in this case will be attached to the free end of said arm, and will be disposed substantially parallel to the vane when the latter is in closed position (horizontal).

In Fig. 8 there is taught a modification of the construction shown in Fig; 7 and comprising either a straight or a curved lever arm 26, so connected to the vane that one portion of said arm lies to one side of the pivot l2 while the other portion lies to the other side thereof, wherefore the spring I! may be disposed substantially vertically.

The construction of Fig. 9 is a modification of that shown in Fig. 8 involving the use of either a straight or a curved leverarm 26, but here said armis attached to the undeirsurface of the closed vane to permit the employment of a\spring disposed horizontally below said vane.

In Fig. 10 is indicated the use of a flat or spring 21 one end of which is rigidly secured to a stationary member 28 and the other end of which bears against the free end of lever B in a direction tending to cause opening movement of the vane I I.- It may be convenient to provide a roller 29 at such bearing point to reduce friction while the lever is moving to its position l3 with coincidental movement of the vane to its open' position ll The use of such a leaf spring may be modified according to the teachings of Figs. 4 to 9 and it should be obvious that coil springs of compression or tension types may be alternatively used in accordance with this disclosure all as found to be most suitable to the particular installation involved. it

The same principles are applicable to the modified form of construction shown in Fig. 11 wherein each vane II is secured to an operating shaft 12 having its end bent to form the crank 30, said crank positioned to provide the desired angle of leverage with respect to the plane of its vane. A spring such as 3| below each vane places the crank thereof under the desired tension, and exerts a force tending to open the vane, as hereinbefore brought out. To insure coincidental movement of all. the vanes a short bar or link such as 32 is rigidly secured to the forward or opening edge of each vane, said links of equal length and extending upwardly, the upper extremities of said links pivotally connected to a tie rod such as 33 disposed above the vanes. Each vane has its rearmost edge extended beyond the shaft I2 a slight distance, such extension being indicated at- 34 as not only providing a short underlap of the next adjacent vane but additionally serving as a stop for said next adjacent vane when in closed position. By this construction, i. e. attaching a pluralityof springs to the plurality of vanes, tension would be substantially equally distributed particularly over a large louvre"; thus avoiding the distortion of the structure which would result from the utilization of a single heavy duty spring operating from a given point. 4

From what has been said hereinbefore it therefore will be understood that a tie rod can be disposed either above or below the plane of the vanes when in closed position, that the operating mechanism for a vane may comprise a lever attached to the vane or it may be an end portion of the vane shaft bent to form a crank, that the tie rod may or may not interconnect the vane levers, and that the tensioning means may be attached to the tie rod or to the vane levers. In other words from the modifications of construction herein disclosed there may be obvious substitutions all, however, resulting in a utilization of the same principle of the invention.

It is obvious that those skilled in the art may vary the details of construction and arrangements of parts without departing from the spirit of this invention and therefore it is desired not except as may be required by the claims.

.to. be limited to the exact foregoing disclosure What is claimed is: 1. In combination an air vent; means to impel an air current through said vent; a pivoted vane horizontally closing saidvent when no air current is flowing through said vent, said vane adapted to be moved against the urge of gravity into vent-opening position when an air pressure of sumcient force is directed against said vane; a lever rigidly connected to said vane at a point ing through the vane pivot; and spring means disposed\on one'side only of such pivotal planeand connected to said lever and exerting a force thereon opposed to the gravitational pull on said vane.

2. In combination an air vent; means to impel an air current through said vent; a pivoted vane horizontally closing said vent when no air current is flowing through said vent, said vane adapted to be moved against the urge of gravity into vent-opening position when an air pressure of sufiicient force is directed against said vane; a lever rigidly connected to said vane at a point intermediate the pivotal and opposite edges of the vane, said lever arcuately formed and substantially centered about the vane pivot, said lever having portions extending to both sides of a plane passing through the vane pivot; and spring means disposed on one side only of such pivotal plane and connected to said lever and exertinga force thereon opposed to the gravitational pull on said vane. 3. The combination with a vertical passageway for air, impeller means for forcing a stream of air therethrough in one direction, and means for preventing the flow of air through said passageway in the opposite direction comprising pivoted shutter means mounted to swing about a horizontal axis from a horizontal 'closed posi-' tion to an inclined open position, of a lever arm rigidly connected at one end to said shutter means, and a spring having one end connected to an anchoring means and the opposite end operatively connected'to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the shutter means and to said anchoring means being such that the distance between the line of spring action'and the pivot.

connected at one end to said shutter means and disposed in a plane forming an acute angle with the plane of the shutter means, and a spring having one end connected to an anchoring means and the opposite end operatively connected to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the anchoring means being such that the l e of spring action is acute 1y inclined to the I lane of said arm, and the relation of .said arm to the shutter means and to said anchoring means being such that the-distance between the line of spring action and the pivot of said shutter means increases as the shutter means moves to its inclined open position when air is being forced through said passageway.

5. The combination with a vertical passageway for air, impeller means for forcing a stream of air therethrough in one direction, and means for preventing the flow of air through said passageway in the opposite direction comprising pivoted shutter means mounted to swing about a horizontal axis from a horizontal closed position to an inclined open position, of a lever arm rigidly connected at one end to said shutter means at a point intermediate the pivotal and opposite edges of said means and extending in a direction away from the plane of said means, and a spring having one end connected to an anchoring means and the opposite end operatively connected to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the anchoring means being such that the spring is disposed entirely to one side of the plane of the shutter means during the opening and closing movements thereof, and the relation of said arm to the shutter means and to said anchoring means being such that the distance between the line of spring action and the pivot of said shutter means increases as the shutter means moves to its inclined open position when air is being forced through said passageway.

6. The combination with a vertical passageway for air, impeller means for forcing a stream of air therethrough in one direction, and means for preventing the flow of air through said passageway in the opposite direction comprising pivoted shutter means mounted to swing about a horizontal axis from a horizontal closed position to an inclined open position, of a lever arm rigidly connected at the end to said shutter means at a point intermediate the pivotal and opposite edges of said means and extending in a direction away from the plane of said means, and a spring having one end connected to an anchoring means and the opposite end operatively con nected to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the anchoring means being such that the plane of the shutter means is disposed between the extremities of the spring during the opening and closing movements of the shutter means, and the relation of said arm to the shutter means and to said anchoring means being such that the distance between the line of spring action and the pivot of said shutter means increases as the shutter means moves to its inclined open position when air is being forced through said passageway.

7. The combination with a vertical passageway for air, impeller means for forcing a stream of air therethrough in one direction, and means for preventing the flow of air through said passageway in the opposite direction comprising pivoted shutter means mounted to swing about a horizontal from a horizontal closed position to an inclined open position, of a lever arm rigidly connected at one end to said shutter means, and a spring having one end connected to an anchoring means the opposite end operatively connected to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the anchoring means being such that the plane of the shutter means is disposed between the extremities of the spring during the opening and closing movements of the shutter means, and the relation of said arm to the shutter means and to said anchoring means being such that the distance between the line of spring action and the pivot of said shutter means increases as the shutter means moves to its inclined open position when air is being forced through said passageway.

8. The combination with a vertical passageway for air, impeller means for forcing a stream of air therethrough in one direction, and means for preventing the flow of air through said passageway in the opposite direction comprising pivoted shutter means mounted to swing about a horizontal axis from a horizontal closed position to an inclined open position, of a lever arm rigidly connected at one end to said shutter means, and a spring having one end connected to an anchoring means and the opposite end operatively connected to the other end of said lever arm, said spring to assist the impeller means to open said shutter means, the relation of said arm to the anchoring means being such that the spring is disposed entirely to one side of the plane of the shutter means during the opening and closing movements thereof, and the relation of said arm to the shutter means and to said anchoring means being such that the distance between the line of spring action and the pivot of said shutter means increases as the shutter means moves to its inclined open position when air is being forced through said passageway.

9. In combination an air vent; means to impel an air current through said vent; a pivoted vane horizontally closing said vent when no air current is flowing through said vent, said vane adapted to be moved against the urge of gravity into vent-opening position when an air pressure of sufiicient force is directed against said vane; a lever rigidly connected to said vane at a point intermediate the pivotal and opposite edges of the vane, said lever having portions extending to both sides of a plane passing through the vane pivot; and spring means disposed on one side only of such pivotal plane and connected to said lever, said spring means to assist the impeller means to open said vane against the gravitational pull on said vane.

LYMAN C. REED. 

